AIM: To investigate the photocatalytic killing effect of photoexcited TiO2 nanoparticles on human colon carcinoma cell line (Ls-174-t) and to study the mechanism underlying the action of photoexcited TiO2 nanoparticle...AIM: To investigate the photocatalytic killing effect of photoexcited TiO2 nanoparticles on human colon carcinoma cell line (Ls-174-t) and to study the mechanism underlying the action of photoexcited TiO2 nanoparticles on malignant cells.METHODS: Ls-174-t human colon carcinoma cells were cultured in RPMI 1640 medium supplemented with 199 mL/L calf serum in a humidified incubator with an atmosphere of 50 mL/L CO2 at 37℃. Viable cells in the samples were measured by using the MTT method. A GGZ-300 W high pressure Hg lamp with a maximum ultraviolet-A (UVA, 320-400nm) irradiation peak at 365 nm was used as light source in the photocatalytic killing test.RESULTS: The photocatalytic killing of Ls-174-t cells was carried out in vitro with TiO2 nanoparticles. The killing effect was weak by using UVA irradialJon without riO2 nanoparticles. In our studies, the photocatalytic killing effect was correlated with the concentration of TiO2 and illumination time. Once TiO2 was added, Ls-174-t cells were killed at a much higher rate. In the presence of 1 000 μg/mL TiO2, 44% of cells were killed after 10 min of UVA irradiation, and 88% of cells were killed after 30 min of UVA irradiation.CONCLUSION: When the concentration of TiO2 is below 200μg/mL, the photocatalytic killing effect on human coloncar cinoma cells is almost the same as that of UVA irradiation alone. When the concentration of TiO2 is above 200μg/mL,the remarkable killing effect of photoexcited riO2 nanoparticles can be found.展开更多
Hydroxy-5-methyl-5, 10- dihydrophenophosphazine 10-oxide (1) was prepared by a new technique of treating 10-methoxy-5,10-dihydrophenophosphazine 10-oxide (2) with an equivalent of NaH in anhydrous DMF, and then at 120...Hydroxy-5-methyl-5, 10- dihydrophenophosphazine 10-oxide (1) was prepared by a new technique of treating 10-methoxy-5,10-dihydrophenophosphazine 10-oxide (2) with an equivalent of NaH in anhydrous DMF, and then at 120C for 3~4 h, which not only avoided poisonous and expensive methyl iodide used in literature, but made the consumption of NaH greatly decrease as well. The possible reaction mechanism was also described. The chemical structure of 1 was confirmed by IR, NMR, and mass spectroscopy.展开更多
Well-cubic perovskite lanthanum aluminate (LaAlO3) film on (110) silicon substrate was fabricated by sol-gel method with corresponding inorganic salts. Lanthanum acetate and aluminum acetate glacial acetic acid solut...Well-cubic perovskite lanthanum aluminate (LaAlO3) film on (110) silicon substrate was fabricated by sol-gel method with corresponding inorganic salts. Lanthanum acetate and aluminum acetate glacial acetic acid solutions were prepared via ligand exchange starting from lanthanum nitrate hexahydrate and aluminum nitrate hexahydrate after being refluxed. (CH3CO)2O removed nitrates and the crystallized H2O completely, acetylacetone (AcAc) was partially bidentated with metallic ion of the metallic acetates and formed La(OAc)3 (AcAc)x, which were hydrolyzed into La(AcAc)3 (OH)x by ?x ?x adding 10 ml 0.4% methyl cellulose (MCL) solution. The La(AcAc)3 (OH)x, polymerizing and combining with MCL, ?x formed the LaAlO3 sol precursor with heteropolymeric structure and formed film easily. The epitaxial LaAlO3 film on Si(110) substrate was crystallized after being annealed in thermal annealing furnace for 650?750 °C/30 min. The mor- phologies and microstructures were characterized. The refractive index of the LAO film was 1.942 to 2.007; the dielectric constant and the dissipation factors were estimated to be 23?26 and 2.1×10?4 ? 2.4×10?4 respectively.展开更多
Ibuprofen is widely used as a non-steroidal anti-inflammatory drug and produced as racemic mixture. Its pharmacological activity resides only in S-(+)-enantiomer, and R-()-enantiomer is not only inactive but also has ...Ibuprofen is widely used as a non-steroidal anti-inflammatory drug and produced as racemic mixture. Its pharmacological activity resides only in S-(+)-enantiomer, and R-()-enantiomer is not only inactive but also has many side effects. Thus it is necessary to separate R-enantiomer from racemic ibuprofen. We studied optical separation of racemic Ibuprofen with chiral high performance liquid chromatography (HPLC). Out of three different chiral stationary phases, which were selected on the basis of structure and availability, two were found to be ef-fective. There was optimum eluent composition for each stationary phase for good resolution in optical separation. Resolution decreased with increase of eluent flow rate, but effect of injection volume on resolution was insignificant at high eluent flow rate.展开更多
A combined physical model of bubble growth is proposed along with a corresponding bubble growth model for binary mixtures on smooth tubes. Using the general model of Wang et al.[1] and the bubble growth model for bina...A combined physical model of bubble growth is proposed along with a corresponding bubble growth model for binary mixtures on smooth tubes. Using the general model of Wang et al.[1] and the bubble growth model for binary mixtures, an analytical model for nucleate pool boiling heat transfer of binary mixtures on smooth tubes is developed.In addition, nucleate pool boiling heat transfer of pure liquids and binary mixtures on a horizontal smooth tube was studied experimentally. The pure liquids and binary mixtures included water,methanol, ethanol, and their binary mixtures. The analytical models for both pure liquids and binary mixtures are in good agreement with the experimental data.展开更多
In the present paper,the mechanism of molecular aggregation and the character of potential function for square-well model have been investigated with the principle of molecular thermodynamics,leading to the potential ...In the present paper,the mechanism of molecular aggregation and the character of potential function for square-well model have been investigated with the principle of molecular thermodynamics,leading to the potential function for double square-well(DSW) model,In addition,the equation of second virial coefficient for DSW model is derived from the statistical mechanics method.The above equation obtained has been verified by tests and the test results are excellent.It is concluded that this equation can well represent the behaviour of fluid molecules.展开更多
A theoretical investigation was conducted to study the transport-reaction process in the spray-drying flue gas desulfurization. A transport-reaction model of single particle was proposed, which considered the water ev...A theoretical investigation was conducted to study the transport-reaction process in the spray-drying flue gas desulfurization. A transport-reaction model of single particle was proposed, which considered the water evaporation from the surface of droplet and the reaction at the same time. Based on this model, the reaction rate and the absorbent utilization can be calculated. The most appropriate particle radius and the initial absorbent concentration can be deduced through comparing the wet lifetime with the residence time, the result shows in the case that the partial pressure of vapor in the bulk flue gas is 2000Pa, the optimum initial radius and absorbent concentration are 210～310 μ m and 23% respectively. The model can supply the optimum parameters for semi-dry FGD system designed.展开更多
基金Supported by the National Natural Science Foundation of China,No.29776032 and the Natural Science Foundation of Shanxi Province,No.971013
文摘AIM: To investigate the photocatalytic killing effect of photoexcited TiO2 nanoparticles on human colon carcinoma cell line (Ls-174-t) and to study the mechanism underlying the action of photoexcited TiO2 nanoparticles on malignant cells.METHODS: Ls-174-t human colon carcinoma cells were cultured in RPMI 1640 medium supplemented with 199 mL/L calf serum in a humidified incubator with an atmosphere of 50 mL/L CO2 at 37℃. Viable cells in the samples were measured by using the MTT method. A GGZ-300 W high pressure Hg lamp with a maximum ultraviolet-A (UVA, 320-400nm) irradiation peak at 365 nm was used as light source in the photocatalytic killing test.RESULTS: The photocatalytic killing of Ls-174-t cells was carried out in vitro with TiO2 nanoparticles. The killing effect was weak by using UVA irradialJon without riO2 nanoparticles. In our studies, the photocatalytic killing effect was correlated with the concentration of TiO2 and illumination time. Once TiO2 was added, Ls-174-t cells were killed at a much higher rate. In the presence of 1 000 μg/mL TiO2, 44% of cells were killed after 10 min of UVA irradiation, and 88% of cells were killed after 30 min of UVA irradiation.CONCLUSION: When the concentration of TiO2 is below 200μg/mL, the photocatalytic killing effect on human coloncar cinoma cells is almost the same as that of UVA irradiation alone. When the concentration of TiO2 is above 200μg/mL,the remarkable killing effect of photoexcited riO2 nanoparticles can be found.
基金The authors would like to acknowledge support from the National Natural Science Foundation of China(29972006) especially to express the deep appreciation to Professor Q. J. Peng and Miss K. Jin from our laboratory for their assistance in performing str
文摘Hydroxy-5-methyl-5, 10- dihydrophenophosphazine 10-oxide (1) was prepared by a new technique of treating 10-methoxy-5,10-dihydrophenophosphazine 10-oxide (2) with an equivalent of NaH in anhydrous DMF, and then at 120C for 3~4 h, which not only avoided poisonous and expensive methyl iodide used in literature, but made the consumption of NaH greatly decrease as well. The possible reaction mechanism was also described. The chemical structure of 1 was confirmed by IR, NMR, and mass spectroscopy.
文摘Well-cubic perovskite lanthanum aluminate (LaAlO3) film on (110) silicon substrate was fabricated by sol-gel method with corresponding inorganic salts. Lanthanum acetate and aluminum acetate glacial acetic acid solutions were prepared via ligand exchange starting from lanthanum nitrate hexahydrate and aluminum nitrate hexahydrate after being refluxed. (CH3CO)2O removed nitrates and the crystallized H2O completely, acetylacetone (AcAc) was partially bidentated with metallic ion of the metallic acetates and formed La(OAc)3 (AcAc)x, which were hydrolyzed into La(AcAc)3 (OH)x by ?x ?x adding 10 ml 0.4% methyl cellulose (MCL) solution. The La(AcAc)3 (OH)x, polymerizing and combining with MCL, ?x formed the LaAlO3 sol precursor with heteropolymeric structure and formed film easily. The epitaxial LaAlO3 film on Si(110) substrate was crystallized after being annealed in thermal annealing furnace for 650?750 °C/30 min. The mor- phologies and microstructures were characterized. The refractive index of the LAO film was 1.942 to 2.007; the dielectric constant and the dissipation factors were estimated to be 23?26 and 2.1×10?4 ? 2.4×10?4 respectively.
文摘Ibuprofen is widely used as a non-steroidal anti-inflammatory drug and produced as racemic mixture. Its pharmacological activity resides only in S-(+)-enantiomer, and R-()-enantiomer is not only inactive but also has many side effects. Thus it is necessary to separate R-enantiomer from racemic ibuprofen. We studied optical separation of racemic Ibuprofen with chiral high performance liquid chromatography (HPLC). Out of three different chiral stationary phases, which were selected on the basis of structure and availability, two were found to be ef-fective. There was optimum eluent composition for each stationary phase for good resolution in optical separation. Resolution decreased with increase of eluent flow rate, but effect of injection volume on resolution was insignificant at high eluent flow rate.
文摘A combined physical model of bubble growth is proposed along with a corresponding bubble growth model for binary mixtures on smooth tubes. Using the general model of Wang et al.[1] and the bubble growth model for binary mixtures, an analytical model for nucleate pool boiling heat transfer of binary mixtures on smooth tubes is developed.In addition, nucleate pool boiling heat transfer of pure liquids and binary mixtures on a horizontal smooth tube was studied experimentally. The pure liquids and binary mixtures included water,methanol, ethanol, and their binary mixtures. The analytical models for both pure liquids and binary mixtures are in good agreement with the experimental data.
文摘In the present paper,the mechanism of molecular aggregation and the character of potential function for square-well model have been investigated with the principle of molecular thermodynamics,leading to the potential function for double square-well(DSW) model,In addition,the equation of second virial coefficient for DSW model is derived from the statistical mechanics method.The above equation obtained has been verified by tests and the test results are excellent.It is concluded that this equation can well represent the behaviour of fluid molecules.
文摘A theoretical investigation was conducted to study the transport-reaction process in the spray-drying flue gas desulfurization. A transport-reaction model of single particle was proposed, which considered the water evaporation from the surface of droplet and the reaction at the same time. Based on this model, the reaction rate and the absorbent utilization can be calculated. The most appropriate particle radius and the initial absorbent concentration can be deduced through comparing the wet lifetime with the residence time, the result shows in the case that the partial pressure of vapor in the bulk flue gas is 2000Pa, the optimum initial radius and absorbent concentration are 210～310 μ m and 23% respectively. The model can supply the optimum parameters for semi-dry FGD system designed.
